Distillation of hydrocarbon oils



All@ 9, 1932 l T. s. co'oKE ET AL. LSH'M' DISTILLATION 0F, HYDROCARBON OILS Fiied July 14. 1928 -Patented Aug. 9, 1932 diagrammatically as a container UNITED STATES PATENT OFFICE THOMAS S. COOKE, OF. NEW YORK, N. Y., AND OSWALD C. BREWSTER, OF CASIER, WYO- MING, ASSIGNORS T0 STANDARD OIL COMPANY, OF WHITING, INDIANA; A CORPORA- TION OF INDIANA DISTILLATION OF HYDROCABBON OILS Application led July 14,

This invention relates to the distillation of hydrocarbon oils and will be readily understood from the following description taken in conjunction with the accompanying drawing, which shows diagrammatically an apparatus suitable for eflecting such distillation.

Referring to the drawing A pipe still 10 is provided, which is adapted to be supplied with oil by the plpe 11. The outlet- 12 from the pipe still 10 leads into a suitable separating chamber 13. From the lower end of the chamber 13 a pipe 14, provided with a suit-able pump '14", leads to a tar heat exchanger 15. Ih the drawing the tar heat exchanger 15 is represented containing a coil 15iL into which the pipe 14 leads. It must be understood that any form of exchanger providing for indirect heat exchanging contact of tar and oil may be used. The tar outlet 16 from the tar heat exchanger 15 communicates with a valved pipe 17 and with a tar cooler 18 so that the tar can be supplied either relatively cold or relatively warm to storage. A pipe 19 connects the pipes 14 and 16 and suitable valves are provided whereby the tar heat exchanger 15 may be bypassed, the tar passing by pipes 14, 19 and 16 direct from the separating chamber 13 to the tar cooler 18.

From the upper portion of theseparating chamber 13 a pipe 20 leads into the lower portion of a fractionating tower 21, which is provided with suitable fractionating devices, for example, bubb1ecap plates 22 and bubble caps 23. From the lower end of the tower 21 a pipe 24 leads into pipe 11. The g pipe 24 is provided with a suitable pump 25.

A pump 26 is provided for supplying oil to be distilled, The outlet27 of the pump 26 leads into the tar heat exchanger 15. From the upper side of the tar heat exchanger 15 a pipe 28 leadsto anointermediateportion of the tower 21 for the purpose of introducing thereinto any vapors formed in the tar heat exchanger 15. The preheated incoming oil emerges from the tar heat exchanger 15 and passes by a pipe 29'to an intermediate point of the fractionating tower 1928. Serial No. 292,661.

21; A pipe 30 connects the pipes 27 and 29 and suitable valves are provided so that the incoming oil may be by-passed with respect to the tar heat exchanger 15, when desired.

The pipe 27 is connected by a pipe 31 to the inlet 11 of the pipe still 10, and suitable valves are provided whereby a desired portion of the incomin oill may be supplied directly to the pipe still. The pipe 14 is connected to the pipe 31 by the pipe 32 and suit# able valves are provided for the purpose of permitting thereturn of a desired amount of the tar from the separating chamber 13 to the pipe still 10. j

From the top of the tower 21 a vapor conduit 33 leads into a suitable condenser 34.

The condensate flows out of said condenser leads into the fractionating tower 21 at asuitable point which is preferably below the plates to which the pipes 38 are connected. l

The tower 40 is provided at its' base with a pipe 42for supplying open steam thereinto, and with a liquid outlet 43 which suitably leads to an 'oil cooler 44, which is suitably cooled by water in known manner. The oil emerges from the oil cooler 44 by the pipe 45. The pipes 17, 35' and 45 arey provlded with suitable valves 46 whereby the apparatus may be maintained under a desired pressure, which, as will be hereinafter indicated, has important advantages in distillation according to this method.

Suitable oat control means (not shown) may be provided in the lower portion of ltowers 21 and 40 and of separating chamber r tively.

v is supplied by the pump 26 through pipe 27V to the tar heat exchanger 15. In passing through the tar heat exchanger 15 the incoming oil is heated to approximately 425 F. by the hot tar which passes through the coil 15". The steam and gasoline vapors which The descending are produced owing to this rise of temperature collect in the upper portion of the heat exchanger and pass by the pipe 28 into an intermediate point of the fractionating tower 21. The preheated liquid oil is conducted by the pipe 29 to an intermediate portion of the tower 21. Said oil descends through the lower plates of the tower 21 countercurrent to the highly heated vapors which are supplied by pipe 20. to a lower point of Athe tower 21, as will be hereinafter further described. oil is deprived of the lighter fractions by t e stripping action of the ascending hot vapors, which are cooled and deprived of certain heavy fractions which are condensed and become part of the descending oil. The temperature of the oilat the bottom of the tower 21 has been increased somewhat, 'for example, to 460 F. to 475 F. This hot oil is supplied by pump 25 through pipes 24 and 11 to the pipe still 10. As i n dicated above, a certain quantity of` incoming crude oil and/or tar may, if desired, be also supplied to the pipe still 10 by the pipes 31 and/or 32, respectively.

In passing through the pipe still 10 the oil is heated to approximately 575 F. and is conducted to the separating chamber 13 by the pipe 12. The vapors formed by the heating in the pipe still separate from the unvaporized liquid in the separating chamber 13 andthe vapors pass by pipe 2O into the lower portion of the column 21 in the manner above described. The tar is pumped by pump 14l through the pipe 14 through' the coil 15a of the heat exchanger 15 and its temperature is thereby reduced to about 175 F. As indicated above, the heat of the tar is communicated to the incoming crude oil in passing through the tar heat exchanger 15. The tar is then passed by pipes 16 and 17 direct to storage or it may be cooled in the tar cooler 18 b water in well known manner.

T e vapors which are admitted into the tower 21 by thev pipe 28 together with the vapors admitted into the tower by the pipe 20 and the vapors which have been stripped from the oildescendingthrough 'the lower part of the tower 21 pass through the plates in the upper portion of said tower countercurrent to reflux supplied by pipe 36.

The upper end of the tower 21 may suitably be maintained at a temperature ofahouty 275 F. by regulating the speed of the reiux pump 37. The distillate is condensed in the water condenser -34 in the usual manner. The valves 46 are so adjusted as to maintain the apparatus including the condenser 34'under substantial pressure, for example, one atmosphere gage. In this way the cooling eiiciency of the condenser water is greatlyl enhanced. For example, relatively warm condenser water, such as water at a temperature of 85 F. is as effective in condensing eii'ect and -gasoline recovery when operating at a pressure of one atmosphere gage, as is water around 50 to 60 F. when operating at atmospheric pressure. Steam in substantial quantit tends to nullify the effect obtained by con ensingunder superatmospheric prcssure. Accordingly it is preferred to avoid as far as possible the introduction of steam or water into the system. It is thus apparent that the present operation is particularly adapted for use under tropical or semi-tropical conditions or where only limited quantities of cooling water are available.

If desired, the kerosene fractions which the crude oil may contain may be readily scparatcd in the following manner: A suitable amount of reiux is drawn off from one'or more of the higher platesof the column 21 by the pipes 38 and ,39 and supplied to the upper end of the small tower 40. Such oil descends through said tower and collects in the bottom thereof. Open steam is supplied lby the pipe 42 in an appropriate amount to strip the oil of sufficient gasoline fractions to yield a satisfactory' kerosene. The steam and light fractions pass by pipe 41 into the tower 21 while the kerosene passes by pipe 43 to the cooler 44 and thence to storage by pipe 45.

It will be noted that during the whole process the oilA is not subjected to cracking temperatures. sures products of remarkable stability and purity so that the necessity of acid treatment of the product is avoided in the case of very many crudes, where it would be necessary if cracking temperatures were attained.

Although the present invention has been described in connection with the details of a specific-example thereof,it must be understood that it'is not intended that such details should be limitative of the scope of the invention except in so far as included in ,the .accompanyin claims.

We c aim:

1. The method of distilling hydrocarbon oils which consists in preheating said oil by indirect contact with highly heated residue thereby vaporizing a part thereof, supplying said vapors to an intermediate point of a fractionating column, supplying unvaporized oil to an intermediate point of said towl,"

This feature of the process enl the vapors therefrom and passing same upwardly through said columnl countercurrent to said descending oil thereby stripping volatile fractions therefrom, subjecting the combined vapors to fractionation, cooling the combined vapors t'o condense heavier portions thereof, subjecting the condensed portions to a stripping operation, returnin the stripped vapors to said fractionating co umn and condensing the-fractionated vapors.

2. The method of distilling hydrocarbon oils which consists in preheating said oil by indirect contact with highly heated residue thereby vaporizing a part thereof, supplying said vapors to an intermediate point of a fractionating tower, supplying unvaporized oil to an intermediate point of said tower and causing same to flow downwardly through the lower part thereof, passing said oil in a confined stream through a heating zone thereby vaporizing a part thereof, separating the vapors therefrom and passing same upwardly through said column countercurrent to said descending oil thereby stripping volatile fractions therefrom, fractionating the combined vapors in the upper portion of said fractionating tower, cooling the vapors to condense va portion thereof withdrawing said condensed portion and subjecting it to a stripping operation, returning the stripped vapors to said fractionating tower, condensing the fractionated vapors and supplying in the top of said tower condensed fractionated vapors to act as refiux therein. y

3. The method of distilling hydrocarbon mineral oils which consists 1n preheating said oil by indirect contact with highly heated residue thereby vaporizing a part thereof, separately withdrawing the vapors from said preheating operation and supplying said vapors to an intermediate point of a fractionating tower, separately withdrawing unvaporized oil from said preheating operation and supplying said unvaporized oil to an intermediate point of said tower and causing same to flow downwardly through the tower part thereof, passing said oil from said column in a confined ystream through a heating zone thereby vaporizing a part thereof without the addition of steam, separating the vapors therefrom and passing same upwardly through said column countercurrent to said descending oil thereby stripping volatile fractions therefrom, fractionating the combined vapors in the upper portion of said fractionating tower, condensing the fractionated vapors under superatmospheric pressure 6D and supplying-in the top of said tower condensed fractionated vapors to act as reflux therein.

4. The method of distilling crude petroleum which consists in supplying said crude petroleum to an intermediateV part of the fractionating tower, causing liquid portions thereof to descend the lower portion of said tower, thereafter heating said liquid portions in a confined stream to vaporize gasoline and kerosene fractions therefrom, passing said cooling medium at the to of said tower to act as reflux therein, withdrawing reflux from an elevated part of said tower, stripping said reiiux with steam to yield refined kerosene and conveying the stripped vapors and steam to said fractionating tower. 5. ,The method of distilling hydrocarbon mineral oils under superatmospheric pressure which consists in preheating said oil to about 425 F. by indirect contact with highly heated residue thereby vaporizing a part of said oil, separately withdrawing the vapors from said preheating operation and supplying said vapors to an intermediate point of a fractionating tower, separately withdrawing unvaporized oil from said preheating operation and supplying said unvaporized oil to an intermediate point of said tower below the pointof introduction of ysaid vapors and causing same to flow downwardly through the lower part thereof, passing said unvaporized oil from said column in a confined stream through a heating zone thereby heatfing it to a temperature of about 57 5 F.1without the addition of steam, separating vapors from said oil and passing same upwardly through said tower countercurrent to said descendlng oil thereby stripping volatile fractions therefrom, subjecting the combined vapors to fractionation and condensing the fractionated vapors.

6. The method of distilling hydrocarbon mineral oils which consists in preheating said oil to about 425 F. by indirect contact with highlylheated residue thereby vaporizingv a part of said oil` separately withdrawing the vapors from said preheating operation and supplying said vapors to an intermediate point of a fractionating tower, separately7 withdrawing unvaporized oil from said preheating operation and supplying said u nvaporized oil to an intermediate point of said tower below the point of introduction of said vapors and causing same to How downwardly through the lower part thereof, passing said unvaporized oil from said column in a conlined stream through a heating zone thereby heating it to a temperature of about 575 F. without the addition of steam, separating vapors from said oil and passing same upwardly through said tower countercurrent to said descending oil thereby stripping volatile fractions therefrom, subjecting v the combined vapors to fractionation and condensing the fractionated vapors under superatmospheric pressure.

7. The method of distilling hydrocarbon mineral oils which consists in preheating said oil to about 425 F. by indirect contact with highly heated residue, stripping the unvaporized oil with highly heated vapors, heating the stripped oil in a confined stream to about 575 F. without the addition of steam, separating the vapors thus produced from the residue, passing said residue to the said preheating operation, and passing said separated va ors to the stripping operation, fractionatlng the vapors from the preheated oil and the stripping operation together, with drawing from said fractionating operation a portion of the resulting condensate and subjecting it to a separate stripping operation, returning the strlpped vapors to said fractionating operation, and condensing them under superatmospheric pressure.

8. The method of distilling hydrocarbon oils which consists in supplying oil to be distilled to an intermediate point of a fractionating tower, withdrawing oil from a low point of said tower and supplying same to a pipe still, heating said oil to about 575 F. therein thereby vaporizing part of the oil, separating vapors from said oil and passin them into said tower at a low point thereo supplying cooling medium to the upper end of said tower to maintain a temperature of about 275 F. therein, withdrawing vapors from the top of said tower and condensing same under superatmospheric pressure, withdrawing liquid from the upper part of` said tower and stripping same to produce kerosene and returning the stripped vapors to the tower.

9. The method of'distilling hydrocarbon oil which consists in preheating said oil to a temperature of about 425 F. by indirect contact with highly heated residue thereby vaporizing part of the oil, supplying said'vapors and the unvaporized oil to an intermediate part of a fractionating tower, withdrawing unvaporized oil from a low oint of said tower and passing same throug a pi e still, heating said oil to about' 575 F. thereln and vaporizing part of the oil, separating the vapors thus produced from the residue, supplying saidresidue to the preheating operation and supplying said vapors to a low point of saidtower, supplying cooling medium to the upper end of said tower to maintain a temperature of about 275 F. therein, withdrawing vapors from the top of said tower and condensing same withdrawing liquid from the upper part of said tower and stripping same to produce kerosene and returning the stripped vapors to the tower.

10. An apparatus for distilling hydrocarbon oils which comprises a preheater, a conduit for supplying oil to be distilled thereto, a fractionating tower, a vapor pipe leading from said preheater to said tower, a conduit for supplying unvaporized oil from said preheater to said tower, a pipe still, means for conveying oil from the base of said tower into said pipe still, a se arating chamber into which said pipe still eeds a conduit for conveying vapors from said chamber to the base of the fractionating tower and a conduit for conveying .residue from said chamber to the preheater.

11. An a aratus for distilling hydrocarbon oils w ich comprises a fractionating tower, a pipe still, a preheater for incoming oil, a conduit for leading oil from said preheater to an elevated point ofysaid tower, a conduit for conducting vapors from said preheater to said tower, a conduit for conducting oil from a low point of said tower into said pipe still, a separating'chamber connected to the outlet of said pipe still, a conduit for conducting vapors from said separating chamber into a low point of said tower and a conduit for conducting residue from said chamber to said preheater.

12. An apparatus for distilling hydrocarbon oils comprising a' fractionating tower, a'

pipe still, a separating chamber connected to aid pipe still, a conduit for supplying oil to be distilled to an intermediate point of the tower, a conduit for conveying oil from the base of said tower to the pipe still, a vapor conduit extending from said separating chamber to the base of said tower, a second tower, conduits for withdrawing liquid from the upper part of the rst tower and supplying it into the upper part of the second tower, a conduit for supplying stripping steam into the base of the second tower, a liquid outlet from the base of the second tower, and a vapor conduit leading from the top of the second tower into the upper pa-rt of the iirst tower.

13. The method of distilling hydrocarbon oils which comprises passing said oil downwardly through a fractionating column, withdrawing said oil from said column and passing it through a heating zone in a conned stream, heating the oil therein to vapor-` ize a part thereof, passing the vapors to said column and causing them to ascend said column countercurrent to said oil whereby the lighter fractions of said oil are vaporized, subjecting the combined vapors to a fractionation operation, withdrawing resulting condensate from said fractionating operation and subjecting it to a stripping operation, returning the resulting stripped vapors to said fractionation operation, and passing the fractionated vapors from said fractionation operation to a condensing operation.

14.The method of distilling hydrocarbon oils which comprises passing said oil downwardly through a fractionating column, withdrawing said oil from said column and passing it through -a heating zone in a confined stream, heating the oil therein to vaporize a part thereof, passing the vapors to said column and causing them to ascend said L column countercurrent to said oil whereby the lighter'fractio'nsof said oil are vaporized, subjecting the combined vapors to a fractionation Operation, withdrawing resulting condensate from said fractionating operation and subjecting it to a stripping operation, re-

turning the resulting stripped vapors to said fractionation operation, withdrawing the stripped condensate from the system, and passing the fractionated vapors from said fractionation Operation to a condensing operation. In testimony whereof we have hereunto set our hands and seals at New York, N. Y., the 18th day of June, 1928, and at Casper, Wyoming, the 7th day of July 1928, respectively.

THOMAS s. COOKE. OSWALD C. BREWSTER. 

